The invention relates to data synchronization in a telecommunications system and particularly to synchronization of data which supplements user data.
Data of portable terminals, such as portable computers, PDA (Personal Digital Assistant) devices, mobile stations or pagers can be synchronized with databases of network applications, desktop applications or other databases of a communications system. Typically, it is data of calendar and e-mail applications that are synchronized. Synchronization has previously been based on the use of different manufacturer-specific protocols that are not compatible with each other. This restricts the use of different terminals and data types and is frequently difficult for the user. In mobile communication, in particular, it is important to acquire and update data irrespective of the terminal or application used. The SyncML (Synchronization Markup Language) has been developed based on the XML language (Extensible Markup Language) for more enhanced practical synchronization of application data. The SyncML synchronization protocol using messages in SyncML format allows data of any application to be synchronized between any networked terminals. Solutions have also been developed for synchronization of device specific data, such as mobile phone settings. An example of device management standards is the SyncML device management which is partly based on the SyncML data synchronization standard enabling data synchronization.
A situation where one user has various terminals, such as mobile phones, has become more common. These mobile stations may have very different properties: the memory capacity of one mobile station may be considerably large whereas the advantages of the other mobile station are its versatile functionality or small size. When the user changes from one mobile station to another, he would also like to transfer all the necessary personal in formation to the other mobile station. Methods have been devised for transferring user data, such as contact cards, calendar entries, SMS messages and images. SyncML synchronization or terminal-specific data transmission programs, for example, can be used for transferring user data. In addition to user data, an increasing amount of various supplementary data related to the function of the device is stored in existing terminals, such as speed dial numbers, call history, user profiles or general data related to a user data unit. It has not been possible to update data of this kind from one device to another by prior art methods because in portable devices, in particular, the data have been presented in very different manners due to their small memory capacity. Furthermore, there has not been a great need to transfer information of this kind from one device to another.